Roof anchor for an existing roof



FIGS. 1 and 2 are respectively front and rear elevational views of a roof anchor for an existing roof showing my new design;

FIG. 3 and 4 are respectively left and right side elevational views thereof;

FIGS. 5 and 6 are respectively top and bottom views thereof; and,

FIG. 7 is a perspective view thereof. 

The ornamental design for the roof anchor for an existing roof, as shown. 